Please make sure every object is named in Spriter. Do this by double clicking the object name in the bone hierarchy view. (there is a control to unhide sprites at the top of this window). In the next build of Spriter, all objects will automatically be given a default name.This plugin does not work with bones at all yet. The import will fail if you attempt to import a boned project.All objects must exist on every frame for it to display correctly. (There will be a new plugin release in a couple of days that fixes this problem).

Please keep in mind as Ashley said, this is still very much in the early stages, so all of the above caveats will be corrected soon. Please report any bugs or suggestions in this thread for now. Kyatric2012-11-19 21:49:55

I purchased Spriter to support this, really excited for a stable version. I tried to test the monster example file, renaming the objects as your instructions said. Everything imported properly, at least there were no error messages. Running the layout I get this error:

@Uberlou, the reason this is happening is because you have to manually name the items in the other animation as well. The next version of Spriter will make this more simple along with having default names. In the meantime, here's the file I've been using.